netdev - Re: [PATCH] don't allow CAP_NET_ADMIN to load non-netdev kernel modules

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110225190205.GA4541@albatros>
Date:	Fri, 25 Feb 2011 22:02:05 +0300
From:	Vasiliy Kulikov <segoon@...nwall.com>
To:	David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	kuznet@....inr.ac.ru, pekkas@...core.fi, jmorris@...ei.org,
	yoshfuji@...ux-ipv6.org, kaber@...sh.net, eric.dumazet@...il.com,
	therbert@...gle.com, xiaosuo@...il.com, jesse@...ira.com,
	Kees Cook <kees.cook@...onical.com>,
	Eugene Teo <eugene@...hat.com>,
	Dan Rosenberg <dan.j.rosenberg@...il.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] don't allow CAP_NET_ADMIN to load non-netdev kernel
 modules

On Fri, Feb 25, 2011 at 10:47 -0800, David Miller wrote:
> From: Vasiliy Kulikov <segoon@...nwall.com>
> Date: Fri, 25 Feb 2011 18:14:14 +0300
> 
> > Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with
> > CAP_NET_ADMIN may load any module from /lib/modules/.  This doesn't mean
> > that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are limited
> > to /lib/modules/**.  However, CAP_NET_ADMIN capability shouldn't allow
> > anybody load any module not related to networking.
> 
> Why go through this naming change, which does break things, instead of
> simply adding a capability mask tag or similar to modules somehow.  You
> could stick it into a special elf section or similar.
>
> Doesn't that make tons more sense than this?

This is not "simply", adding special section for a single workaround
seems like an overkill for me - this touches the core (modules'
internals), which is not related to the initial CAP_* problem at all.

I'd be happy with not breaking anything, but I don't see any acceptable
solution.


Thanks,

-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html